mac address to pup network/host mapping

[nbriggs]

I've got a piece of C code that implements the mac address to pup network and host number mapping, replicating the functionality that the DiCentra gateways used to provide.
At the moment, it uses a sqlite3 database that one makes entries in by hand -- for example:

% sqlite3 /var/tmp/pup.sqlite3 
SQLite version 3.43.2 2023-10-10 13:08:14
Enter ".help" for usage hints.
sqlite> INSERT INTO mac_pup_mapping VALUES(X'48d705c0eaa2',0,42);
sqlite> .quit

to assign PUP network 0 (local, no internetwork routing) and PUP host 42, to the machine at 48:d7:05:c0:ea:a2 (aka NS address 0#44327.2700.165241#, NS host number (NSHOSTNUMBER 18647 1472 60065)).
With the mapper running with that entry on my mac, it can do:

(\LOOKUPPUPNUMBER \MY.NSHOSTNUMBER)
42

The question I'd like some feedback on is: Would you find it more useful if, when the database does not contain a mapping, it assigned (and remembered) a unique PUP host number automatically?

[masinter]

Would you find it more useful if, when the database does not contain a mapping, it assigned (and remembered) a unique PUP host number automatically?

I can imagine some circumstances where you want to look up whether there is a number without the assigining of a new one.